Here is the full list of all 48 Persona 3 Reload achievements.
Defeated the Chariot and Justice.
Dealt over 999 damage in a single attack (All-Out Attacks excluded).
Unlocked access to the remaining Major Arcana.
Aced an exam.
Nursed a cat back to full health.
Defeated the Hierophant and the Lovers.
Performed a fusion with three or more Personas.
Obtained an item from a Persona Conception.
Performed 50 All-Out Attacks.
Rescued a missing person.
Harvested a crop that you grew with a teammate.
Spent an evening in the dorm with a teammate.
Obtained 10 Major Arcana during Shuffle Time.
Earned over a total of 50,000 yen from part-time jobs.
Defeated the Empress and Emperor.
Maxed out one Social Link.
Ordered from a secret menu at the Iwatodai strip mall at night.
Opened 50 treasure chests.
Initiated 50 Chance Encounters.
Defeated the Priestess.
Triggered a skill change during fusion.
Obtained 10 Personas during Shuffle Time.
Performed a Shift.
Defeated a rare, golden enemy.
Performed a Dyad Fusion.
Joined the Specialized Extracurricular Execution Squad.
Obtained Orpheus.
Defeated the Hermit.
Defeated Fortune and Strength.
Defeated the Hanged Man.
Sealed Nyx.
Watched the good ending.
Invited Elizabeth to your room.
Maxed out all Social Links.
Unlocked all Social Links.
Nurtured a romance.
Awakened all teammates' ultimate Personas.
Used all teammates' Theurgy.
Discovered and conquered 10 Monad doors.
Used a total of 50 Twilight Fragments.
Encountered a Dark Zone in Tartarus.
Defeated the Reaper.
Fused Messiah.
Maxed out one Social Stat.
Maxed out all Social Stats.
Accepted an invitation to hang out five times.
Unlocked a teammate's Combat Characteristic.
Acquired every Twilight Fragment in town.